[Kimchi-devel] [PATCH 3/5] CDROM Management: Devices management model implementation

Rodrigo Trujillo rodrigo.trujillo at linux.vnet.ibm.com
Fri Feb 14 17:50:50 UTC 2014


Reviewed-by: Rodrigo Trujillo <rodrigo.trujillo at linux.vnet.ibm.com>

On 02/14/2014 03:26 PM, Aline Manera wrote:
> From: Rodrigo Trujillo <rodrigo.trujillo at linux.vnet.ibm.com>
>
> This patch adds the CREATE, LOOKUP, UPDATE and DELETE functionalities
> to guest storage devices support.
>
> Signed-off-by: Rodrigo Trujillo <rodrigo.trujillo at linux.vnet.ibm.com>
>
> Using lxml and objectify to parse the XML info.
> Pep8 adjustments in model/vms.py
> Removing hard disk support from model/vms.py
> Including xml creation using lxml in _get_storage_xml
> Including existing device name verification
> Changed model/vms.py to use the new exception model.
>
> Signed-off-by: Daniel Henrique Barboza <danielhb at linux.vnet.ibm.com>
> ---
>   src/kimchi/model/vmstorages.py |  221 ++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 221 insertions(+)
>   create mode 100644 src/kimchi/model/vmstorages.py
>
> diff --git a/src/kimchi/model/vmstorages.py b/src/kimchi/model/vmstorages.py
> new file mode 100644
> index 0000000..1597d49
> --- /dev/null
> +++ b/src/kimchi/model/vmstorages.py
> @@ -0,0 +1,221 @@
> +#
> +# Project Kimchi
> +#
> +# Copyright IBM, Corp. 2014
> +#
> +# Authors:
> +#  Rodrigo Trujillo <rodrigo.trujillo at linux.vnet.ibm.com>
> +#  Daniel Henrique Barboza <danielhb at linux.vnet.ibm.com>
> +#
> +# This library is free software; you can redistribute it and/or
> +# modify it under the terms of the GNU Lesser General Public
> +# License as published by the Free Software Foundation; either
> +# version 2.1 of the License, or (at your option) any later version.
> +#
> +# This library is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +# Lesser General Public License for more details.
> +#
> +# You should have received a copy of the GNU Lesser General Public
> +# License along with this library; if not, write to the Free Software
> +# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
> +
> +import os
> +import re
> +import socket
> +import string
> +import urlparse
> +
> +import libvirt
> +import lxml.etree as ET
> +from lxml import etree, objectify
> +from lxml.builder import E
> +
> +from kimchi.exception import InvalidOperation, InvalidParameter, NotFoundError
> +from kimchi.exception import OperationFailed
> +from kimchi.model.vms import DOM_STATE_MAP, VMModel
> +from kimchi.utils import check_url_path
> +
> +DEV_TYPE_SRC_ATTR_MAP = {'file': 'file',
> +                         'block': 'dev'}
> +
> +
> +class VMStoragesModel(object):
> +    def __init__(self, **kargs):
> +        self.conn = kargs['conn']
> +
> +    def _get_storage_xml(self, params):
> +        src_type = params.get('src_type')
> +        disk = E.disk(type=src_type, device=params.get('type'))
> +        disk.append(E.driver(name='qemu', type='raw'))
> +        # Working with url paths
> +        if src_type == 'network':
> +            output = urlparse.urlparse(params.get('path'))
> +            host = E.host(name=output.hostname, port=
> +                          output.port or socket.getservbyname(output.scheme))
> +            source = E.source(protocol=output.scheme, name=output.path)
> +            source.append(host)
> +            disk.append(source)
> +        else:
> +            # Fixing source attribute
> +            source = E.source()
> +            source.set(DEV_TYPE_SRC_ATTR_MAP[src_type], params.get('path'))
> +            disk.append(source)
> +
> +        disk.append(E.target(dev=params.get('dev'), bus='ide'))
> +        return ET.tostring(disk)
> +
> +    def create(self, vm_name, params):
> +        dom = VMModel.get_vm(vm_name, self.conn)
> +        if DOM_STATE_MAP[dom.info()[0]] != 'shutoff':
> +            raise InvalidOperation('KCHCDROM0011E')
> +
> +        # Use device name passed or pick next
> +        dev_name = params.get('dev', None)
> +        if dev_name is None:
> +            params['dev'] = self._get_storage_device_name(vm_name)
> +        else:
> +            devices = self.get_list(vm_name)
> +            if dev_name in devices:
> +                raise OperationFailed('KCHCDROM0004E', {'dev_name': dev_name,
> +                                                        'vm_name': vm_name})
> +
> +        # Path will never be blank due to API.json verification.
> +        # There is no need to cover this case here.
> +        path = params['path']
> +
> +        # Check if path is an url
> +        if check_url_path(path):
> +            params['src_type'] = 'network'
> +        # Check if path is a valid local path
> +        elif os.path.exists(path):
> +            if os.path.isfile(path):
> +                params['src_type'] = 'file'
> +            else:
> +                # Check if path is a valid cdrom drive
> +                with open('/proc/sys/dev/cdrom/info') as cdinfo:
> +                    content = cdinfo.read()
> +
> +                cds = re.findall("drive name:\t\t(.*)", content)
> +                if not cds:
> +                    raise InvalidParameter("KCHCDROM0003E", {'value': path})
> +
> +                drives = [os.path.join('/dev', p) for p in cds[0].split('\t')]
> +                if path not in drives:
> +                    raise InvalidParameter("KCHCDROM0003E", {'value': path})
> +
> +                params['src_type'] = 'block'
> +        else:
> +            raise InvalidParameter("KCHCDROM0003E", {'value': path})
> +
> +        # Add device to VM
> +        dev_xml = self._get_storage_xml(params)
> +        try:
> +            conn = self.conn.get()
> +            dom = conn.lookupByName(vm_name)
> +            dom.attachDeviceFlags(dev_xml, libvirt.VIR_DOMAIN_AFFECT_CURRENT)
> +        except Exception as e:
> +            raise OperationFailed("KCHCDROM0008E", {'error': e.message})
> +        return params['dev']
> +
> +    def _get_storage_device_name(self, vm_name):
> +        dev_list = [dev for dev in self.get_list(vm_name)
> +                    if dev.startswith('hd')]
> +        if len(dev_list) == 0:
> +            return 'hda'
> +        dev_list.sort()
> +        last_dev = dev_list.pop()
> +        # TODO: Improve to device names "greater then" hdz
> +        next_dev_letter_pos = string.ascii_lowercase.index(last_dev[2]) + 1
> +        return 'hd' + string.ascii_lowercase[next_dev_letter_pos]
> +
> +    def get_list(self, vm_name):
> +        dom = VMModel.get_vm(vm_name, self.conn)
> +        xml = dom.XMLDesc(0)
> +        devices = objectify.fromstring(xml).devices
> +        storages = [disk.target.attrib['dev']
> +                    for disk in devices.xpath("./disk[@device='disk']")]
> +        storages += [disk.target.attrib['dev']
> +                     for disk in devices.xpath("./disk[@device='cdrom']")]
> +        return storages
> +
> +
> +class VMStorageModel(object):
> +    def __init__(self, **kargs):
> +        self.conn = kargs['conn']
> +        self.kargs = kargs
> +
> +    def _get_device_xml(self, vm_name, dev_name):
> +        # Get VM xml and then devices xml
> +        dom = VMModel.get_vm(vm_name, self.conn)
> +        xml = dom.XMLDesc(0)
> +        devices = objectify.fromstring(xml).devices
> +        disk = devices.xpath("./disk/target[@dev='%s']/.." % dev_name)
> +        if not disk:
> +            return None
> +        return disk[0]
> +
> +    def lookup(self, vm_name, dev_name):
> +        # Retrieve disk xml and format return dict
> +        disk = self._get_device_xml(vm_name, dev_name)
> +        if disk is None:
> +            raise NotFoundError("KCHCDROM0007E", {'dev_name': dev_name,
> +                                                  'vm_name': vm_name})
> +        source = disk.source
> +        path = ""
> +        if source is not None:
> +            src_type = disk.attrib['type']
> +            if src_type == 'network':
> +                host = source.host
> +                path = (source.attrib['protocol'] + '://' +
> +                        host.attrib['name'] + ':' +
> +                        host.attrib['port'] + source.attrib['name'])
> +            else:
> +                path = source.attrib[DEV_TYPE_SRC_ATTR_MAP[src_type]]
> +        dev_type = disk.attrib['device']
> +        return {'dev': dev_name,
> +                'type': dev_type,
> +                'path': path}
> +
> +    def delete(self, vm_name, dev_name):
> +        # Get storage device xml
> +        disk = self._get_device_xml(vm_name, dev_name)
> +        if disk is None:
> +            raise NotFoundError("KCHCDROM0007E",
> +                                {'dev_name': dev_name,
> +                                 'vm_name': vm_name})
> +
> +        dom = VMModel.get_vm(vm_name, self.conn)
> +        if DOM_STATE_MAP[dom.info()[0]] != 'shutoff':
> +            raise InvalidOperation('KCHCDROM0011E')
> +
> +        try:
> +            conn = self.conn.get()
> +            dom = conn.lookupByName(vm_name)
> +            dom.detachDeviceFlags(etree.tostring(disk),
> +                                  libvirt.VIR_DOMAIN_AFFECT_CURRENT)
> +        except Exception as e:
> +            raise OperationFailed("KCHCDROM0010E", {'error': e.message})
> +
> +    def update(self, vm_name, dev_name, params):
> +        dom = VMModel.get_vm(vm_name, self.conn)
> +        if DOM_STATE_MAP[dom.info()[0]] != 'shutoff':
> +            raise InvalidOperation('KCHCDROM0011E')
> +
> +        info = self.lookup(vm_name, dev_name)
> +        backup_params = info.copy()
> +
> +        info.update(params)
> +        kargs = {'conn': self.conn}
> +        stgModel = VMStoragesModel(**kargs)
> +        try:
> +            self.delete(vm_name, dev_name)
> +            return stgModel.create(vm_name, info)
> +        except Exception as e:
> +            try:
> +                stgModel.create(vm_name, backup_params)
> +            except:
> +                pass
> +
> +            raise OperationFailed("KCHCDROM0009E", {'error': e.message})




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